The Usefulness of Positron Emission Tomography/Computed Tomography in the Diagnosis of Metastasis in Patients with Urothelial Carcinoma — A Secondary Publication

Abstract

Purpose: This study examined the usefulness of positron emission tomography (PET)/computed tomography (CT) in the diagnosis of metastasis in patients with urothelial carcinoma. Materials and methods: The subjects were patients who were newly diagnosed with urothelial carcinoma in our department on whom we performed CT and PET/CT to search for metastasis. Results: The median age of the 92 subjects was 71 years, and bladder and upper tract urothelial cancer were underlying diseases in 41 (46%) and 51 (54%) patients, respectively. In 66 (72%) of the 92 cases, no metastasis was observed by CT, while PET/CT revealed metastasis in 9 (14%). The 57 (86%) patients in whom both CT and PET/CT showed no metastasis underwent radical surgery, while 2 patients (4%) exhibited pathological lymph node metastasis. Of the 26 patients in whom CT revealed metastasis, PET/CT showed no metastasis in 3 (12%), and the absence of pathological metastasis was confirmed in all patients. Of the 23 patients found to have metastasis in both CT and PET/CT, metastasis that could not be identified by CT was discovered by performing PET/CT in 10 (43%) patients. PET/CT showed significantly higher diagnostic accuracy than CT alone (P < 0.01), with sensitivities of 94.1% and 67.6%, specificities of 100% and 94.8%, and accuracy rates of 97.8% and 84.7%, respectively. Conclusions: PET/CT of patients with urothelial cancer revealed that metastases that cannot be diagnosed by CT alone are found at a significant frequency. Since these metastases can affect treatment choices in patients with urothelial cancer, PET/CT is considered to be useful in diagnosing metastases in patients with urothelial cancer.